Validation of the Modified Ashworth scale in Russia

Spasticity after stroke is a factor that causes disability and restricts activities of daily living, and presents a problem for both doctors and patients' relatives. At the present time, the Modified Ashworth scale (MAS) is a useful method of assessing increased muscle tone in patients after a cerebrovascular incident. The aim of the work is the linguistic and cultural adaptation of the MAS, with subsequent evaluation of its psychometric properties. Materials and methods: The study included 50 patients. The validation procedure consisted of linguistic and cultural adaptation and evaluation of the psychometric properties of the Russian language version of the MAS. Test-retest was used to examine reliability (calculating Spearman's rank correlation coefficient) and Cohen's kappa coefficient was used to evaluate inter-rater agreement. Criterion validity was assessed by comparing the MAS results with the Spasticity Scale score of the Research Centre of Neurology. Sensitivity was measured using Wilcoxon nonparametric test, which reflects the statistical significance of intertest differences before and after rehabilitation measures. Results: Test-retest analysis showed a significant correlation (ρ=0.87) between reassessment results. Inter-rater reliability was average (ρ=0.56), which confirms the scale's subjectivity and proves that patient assessment over time should be performed by the same investigator whenever possible. The correlation coefficient between the MAS and the Spasticity Scale of the Research Centre of Neurology was ρ=0.79. Statistically significant differences were found when patients were reassessed after rehabilitation treatment (p<0.0001). Conclusion: The Russian version of the MAS is a valid, reliable and sensitive instrument, which can be recommended for use in clinical practice, both for the initial assessment of spasticity and for monitoring the effect of treatment. © 2020 Sovero Press Publishing House. All rights reserved.